1 /* SPDX-License-Identifier: GPL-2.0+
2  *
3  *  Copyright (C) 2012, Analog Devices Inc.
4  *	Author: Lars-Peter Clausen <lars@metafoo.de>
5  */
6 
7 #ifndef __SOUND_DMAENGINE_PCM_H__
8 #define __SOUND_DMAENGINE_PCM_H__
9 
10 #include <sound/pcm.h>
11 #include <sound/soc.h>
12 #include <linux/dmaengine.h>
13 
14 /**
15  * snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM
16  *   substream
17  * @substream: PCM substream
18  */
19 static inline enum dma_transfer_direction
snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream * substream)20 snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)
21 {
22 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
23 		return DMA_MEM_TO_DEV;
24 	else
25 		return DMA_DEV_TO_MEM;
26 }
27 
28 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
29 	const struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config);
30 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
31 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
32 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
33 
34 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
35 	struct dma_chan *chan);
36 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
37 
38 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
39 	dma_filter_fn filter_fn, void *filter_data);
40 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
41 
42 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
43 	void *filter_data);
44 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
45 
46 /*
47  * The DAI supports packed transfers, eg 2 16-bit samples in a 32-bit word.
48  * If this flag is set the dmaengine driver won't put any restriction on
49  * the supported sample formats and set the DMA transfer size to undefined.
50  * The DAI driver is responsible to disable any unsupported formats in it's
51  * configuration and catch corner cases that are not already handled in
52  * the ALSA core.
53  */
54 #define SND_DMAENGINE_PCM_DAI_FLAG_PACK BIT(0)
55 
56 /**
57  * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
58  * @addr: Address of the DAI data source or destination register.
59  * @addr_width: Width of the DAI data source or destination register.
60  * @maxburst: Maximum number of words(note: words, as in units of the
61  * src_addr_width member, not bytes) that can be send to or received from the
62  * DAI in one burst.
63  * @slave_id: Slave requester id for the DMA channel.
64  * @filter_data: Custom DMA channel filter data, this will usually be used when
65  * requesting the DMA channel.
66  * @chan_name: Custom channel name to use when requesting DMA channel.
67  * @fifo_size: FIFO size of the DAI controller in bytes
68  * @flags: PCM_DAI flags, only SND_DMAENGINE_PCM_DAI_FLAG_PACK for now
69  */
70 struct snd_dmaengine_dai_dma_data {
71 	dma_addr_t addr;
72 	enum dma_slave_buswidth addr_width;
73 	u32 maxburst;
74 	unsigned int slave_id;
75 	void *filter_data;
76 	const char *chan_name;
77 	unsigned int fifo_size;
78 	unsigned int flags;
79 };
80 
81 void snd_dmaengine_pcm_set_config_from_dai_data(
82 	const struct snd_pcm_substream *substream,
83 	const struct snd_dmaengine_dai_dma_data *dma_data,
84 	struct dma_slave_config *config);
85 
86 
87 /*
88  * Try to request the DMA channel using compat_request_channel or
89  * compat_filter_fn if it couldn't be requested through devicetree.
90  */
91 #define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
92 /*
93  * Don't try to request the DMA channels through devicetree. This flag only
94  * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
95  */
96 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
97 /*
98  * The PCM is half duplex and the DMA channel is shared between capture and
99  * playback.
100  */
101 #define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
102 /*
103  * The PCM streams have custom channel names specified.
104  */
105 #define SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME BIT(4)
106 
107 /**
108  * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
109  * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
110  *   PCM substream. Will be called from the PCM drivers hwparams callback.
111  * @compat_request_channel: Callback to request a DMA channel for platforms
112  *   which do not use devicetree.
113  * @process: Callback used to apply processing on samples transferred from/to
114  *   user space.
115  * @compat_filter_fn: Will be used as the filter function when requesting a
116  *  channel for platforms which do not use devicetree. The filter parameter
117  *  will be the DAI's DMA data.
118  * @dma_dev: If set, request DMA channel on this device rather than the DAI
119  *  device.
120  * @chan_names: If set, these custom DMA channel names will be requested at
121  *  registration time.
122  * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
123  * @prealloc_buffer_size: Size of the preallocated audio buffer.
124  *
125  * Note: If both compat_request_channel and compat_filter_fn are set
126  * compat_request_channel will be used to request the channel and
127  * compat_filter_fn will be ignored. Otherwise the channel will be requested
128  * using dma_request_channel with compat_filter_fn as the filter function.
129  */
130 struct snd_dmaengine_pcm_config {
131 	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
132 			struct snd_pcm_hw_params *params,
133 			struct dma_slave_config *slave_config);
134 	struct dma_chan *(*compat_request_channel)(
135 			struct snd_soc_pcm_runtime *rtd,
136 			struct snd_pcm_substream *substream);
137 	int (*process)(struct snd_pcm_substream *substream,
138 		       int channel, unsigned long hwoff,
139 		       void *buf, unsigned long bytes);
140 	dma_filter_fn compat_filter_fn;
141 	struct device *dma_dev;
142 	const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
143 
144 	const struct snd_pcm_hardware *pcm_hardware;
145 	unsigned int prealloc_buffer_size;
146 };
147 
148 int snd_dmaengine_pcm_register(struct device *dev,
149 	const struct snd_dmaengine_pcm_config *config,
150 	unsigned int flags);
151 void snd_dmaengine_pcm_unregister(struct device *dev);
152 
153 int devm_snd_dmaengine_pcm_register(struct device *dev,
154 	const struct snd_dmaengine_pcm_config *config,
155 	unsigned int flags);
156 
157 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
158 	struct snd_pcm_hw_params *params,
159 	struct dma_slave_config *slave_config);
160 
161 #define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"
162 
163 #endif
164